Coal cutting machine



Dec. 20, 1932. n N, |'3 LEVlN "1,891,561

COAL CUTTING MACHINE original' Filed Nov. 1, 1928 3 sheets-sheet 1 Dec. 20, 1932. N. D. I EvlN COAL CUTTING MACHINE Original Filed Nov. l, 1928 s sheets-sheet l2 Dec. 20, 1932. N. D LEVlN 1,891,561

i COAL CUTTING MACHINE original Filed Nov. 1, 1928 s sheets-sheet 5 Fig. 10

L@ da@ dl d Patented Dec. Z0, 1932 muri-:1) STATES PATENT lorricls NILS D. LEVIN, F COLUMBUS, OHIO, ASSIGNOR TO THE JEFFREY MANUFAGTURNG COMPANY, 0F COLMBUS, OHIO, A CORPORATION OF 02H10Y COAL CUTTING MACHINE Application filed November 1, 1928, Serial No. 316,584. f Renewed April 10, 1931.

The present inventionrelates to certain new and useful improvements in coal cutting machines and particularly to machinesv of the class comprising a frameadapted to rest upon and slide in any direction over themine floor, a kerf cutter projecting horizontally therefrom, winding devices mounted upon the main frameand flexible draft devices attached to and windable upon said winding devices adapted to cooperate with anchoring devices external 'of the machine to move and guide it relative to the material to be mined.

It is the especial object of this invention to provide, in a machine of the class described, an improved arrangement of parts whereby the external dimensions of the machine may be reduced without impairment of the efliciency, strength or durability of the machine.

A further' object is to provide improved feeding and guiding mechanism of extreme simplicity of design and eiiiciency of operation.

`A further object is to provide improved controlling mechanism for said feeding and guiding mechanism.

i The means whereby 1 attain these objects are fully set forth in the following specification and illustrated in the accompanying drawings of which Fi 1 is a plan view of the preferred embodiment of my invention.

Fig. 2 is aside elevation of the machine illustrated in Fig. 1.

Fig. 3 is a sectional view taken along the line 111-111 of Fig. 1.

Fig. el is a fragmentary'plan view of the rearward part of the machine illustrated in Figs. 1 and 2, certain parts being removed to reveal the parts below.

Fig. is a sectional view taken along the line V-V of Fig. 4.

6 is a detail of the actuating mechanism of the feed rope winding drum.

Fig. 7 is a sectional view taken along the line VI-VII of Fig. 4.

8 is a sectional view taken along the line VH1-VIII of Fig. 4.

Figs. 9 and 10 and 11 are diagrams illustratmg methods of operating the machine.

Like numerals refer to similar parts in the Vtion 3a, and shoe 3b are in tongue and groove connection with the middle section vas indicated at 10, 30, and 3d respectively. The middle section 2 is shaped to form the magnetic field frame of an electric motor by which the operative parts of the machine are actuated, and these parts are so proportioned and arranged that the height of the motor frame substantially limits the vertical dimensions of the machine. Within the vmagnetic field frame thus provided there is mounted an armature 4 which extends longitudinally of the machine and is supported in suitable bearings not shown in the drawings. The motor above described is providedv with suitable electric controlling devices and is connectible through any suitable and l convenient means with a lsource of electric current supply, but as such devices are well understood in the mining machine art, and as they form noypart in the present invention their illustration and def scription is not thought to be required at this time.

The forward frame section 1 is shaped to form the journal bearing 5 wherein is rotatably supported the vertical shaft 6. Mounted concentrically with the shaft 6 and freely rotatable relative thereto is a bevel gear 7 having a hub 8 the outer surface of which is journaled in a bearing 9 ofthe extension frame 1. lVithin the hub 8 of the gear 7 i is formed afjournal bearing 10 whereiny isrotatably supported rthe upper end of the shaft 6@ The bevel gear 7 meshes with a bevel pinion 11 (shown by dotted lines in Fig. 1

of the drawings) fixed to thearmature shaft 4 of the motor whereby the gear 7 is rotated about its axis.

Slidably mounted upon the shaft 6 and rotatably connected thereto by a suitable feather key, is a clutch member 12 having clutch teeth 13 adapted to engage corresponding teeth 14 formed on a gear member 25. The clutch member 12 is engaged by a clutch collar 15 which is connected with a shifting lever 16 supported upon the pivot pin 17 of the extension frame. This lever 16 is adapted to be oscillated about said pivot pin by an eccentric 18 fixed to the shaft 19 journaled in suitable bearings of the extension frame. At its outer end the shaft 19 is pierced by a suitable aperture through which extends the operating handle 2O which is longitudinally slidable transversely of the shaft 19. These parts are so proportioned and arranged that by manipulation of the handle 20 the shaft 19 may be rotated to cause the eccentric 18 to oscillate the lever 16 and thereby shift the clutch member 12 into or out of engagement with the gear member 7. The handle 20 is also adapted to be placed in such engagement with a flange 21 of the extension frame that it will holdl these parts in the desired relation.

Keyed to the shaft 6 is a sprocket wheel 22 which engages the cutter chain 23. j rlhe chain 23 is adapted to travelin guideways formed on the lateral edges of the cutter arm 24 which projects horizontally from the extension frame 1 in the manner which is well understood in the mining machine art. The spacing of the side runs of the chain, Figure 3, is such as to bring` th-em within the lateral edges of the shoe 1b so that in shoveling slack at the head of the machine, the shovel will strike the shoe instead of the bits.

Fixed to the bevel gear 7 concentric therewith is a bevel gear 25 which engages a similar gear 26 keyed to the horizontal shaft 27 journaled in suitable hearings of the extension frame 1. Formed integral with the shaft 27 is a segmental flange 28 having a surface 29 adapted to engage a suitable clutch memloer 30 formed integral with a hub member 31, The hub member 31 is longitudinally slidable upon the shaft 27 so that. the clutch member 30 may be placed in or removed from operative relation from the flange 28. Two spaced apart annular grooves 32 and 33 formed in the hub member 31 are adapted to be engaged by a detent pin 34 'to hold these parts in the desired relation to each other. Formed on the outer end of the hub 31 is a sprocket wheel 35 adaptedto be engaged by a suitable endless chain whereby rotative power may be transmitted from the mining machine motor to the axles of a. supporting truck when the mining machine is loaded thereon, to propel said truck along the rails of the mine track.

Within the rearward section 3 of the machine frame is supported the feeding and guiding mechanism which comprises two winding drums 36 and 27 symmetrically placed on either side of the longitudinal center line of the machine directly above shoe 3b, and upon these drums are windable the flexible draft elements 38 and 39, preferably wire rope, adapted to be secured to anchoring devices external of t-he machine. The drums 36 and 37 are substantially alike and each is journaled upon a hub 40 which is eccentrically rotatable about a fixed vertical pin 41. The ends of pins 41, as in Figure 7, are reduced, forming shoulders resting against the lower vwall of portion 3a and shoe 3b. The reduced ends are threaded and nuts are screwed thereon above ythe wall and beneath the shoe. Pins 41 are thus adapted totake both tensional and compressive strains. Formed integral with each of the hubs 40 is a lever 42 whereby said hubs may be rotated to move the central axis of the respective drums relative to the vertical shafts 43 and 44 which are journaled in the frame portion 3a with their lower ends projecting freely therebelow. A pin 45 adapt-ed to engage registering apertures in the frame casting and in each of the levers 42 serves to lock the hubs in the preferred position of angular adjustment. Each-of the drums 36 and 37 is provided with a bottom web and with internal gear teeth adapted to engage the teeth of the pinions 46 and 47 which are formed integral with the shafts 43 and 44 on their downwardly projecting ends. The proportions and arrangement of these parts are such that by movement of the lever 42 the internal gear teeth of the drums may be brought into engagement with said pinions to rotate said drums in a direction to wind the ropes, or may be moved out of such engagement to permit their free rotation in the unwinding direc-tion.

Mounted concentrically with the shaft 43 within the frame portion3a is a worm gear 48 which engages a worm 49 formed integral with the extension 50 of the'armature shaft 4 of the motor. The worm gear 48 is fixed to the driving member 51 of a multiple disc friction clutch the driven `member 52 of which is fixed to the shaft 43. These clutch members are adapted to be operatively connected by the clutch discs 53 when pressure is applied thereto through the pressure pins 54. The pins 54 are attached to a collar adapted to be engaged by a thrust collar 56 screw threaded upon the outer surface of the journal bearing 57 in which the upper end of the shaft 43 is supported. `The arrangement of these parts is such that rotationof the thrust collar 56 in one direction screws said collar downwardly to exert pressure upon the pins 54, while its rotation in the opposite direction screws said collar upwardly to relieve that pressure.

Formed integral with the thrust collar56 is a sprocket wheel 58 around which passes an endless chain 59 whereby said thrust collar is operatively connected with the sprocket wheel 60 fixed to a vertical shaft 61 journalled in suitable bearings of the machine frame. The shaft 61 is connected with a horizontal shaft 62 by a pair of mitre gears 63 and 64, and to the shaft 62 is fixed a hand wheel 65, positioned convenient to the hand of the operator. By manipulation of the hand wheel 65 the thrust collar 56 may be rotated to control the actuation of the friction clutch and thereby control the rotation of the winding drum 36.

Keyed to the sha-ft 44 is the driven member 66 of a multiple disc friction clutch the driving member 67 of which is rotatably mounted upon the hub 68 of said driven member. These clutch members are adapted to be operatively connected together by a plurality of friction discs 69 when said discs are pressed together by the pressure pins 70. rlhe pins 70 are attached to a ring 71 adaptedk to be engaged by a thrust collar 72 screw threaded to the outer surface of the journal bearing 73 in which the upper end of the shaft 44 is supported. Formed integral with the thrust collar 7 2 is a sprocket wheel 74 around which passes an endless chain 75 by which said thrust collar is operatively connected with a sprocket wheel 76 fixed to a vertical shaft 77 supported in suitablebearings of the machine frame. The vertical shaft 7 7 is `connected with the horizontal shaft 78 by suitable mitre gears, and to this horizontal shaft 78 is fixed a hand wheel 79 positioned convenient to the hand of the operator. By manipulation of the hand wheel 79 the thrust collar 72 may be rotated in one direction to screw it downwardly to apply pressure upon the disc 69 to connect the driving member 67 with the shaft 44, or it may be rotated in the opposite direction to screw said collar upwardly to relieve that pressure.

An eccentric 80 formed integral with the driving clutch member 51, and thereby fixed to the worm gear 48, is engaged by an eccentric strap 81. An eccentric rod 812 formed integral with the eccentric strap 81 is connected by a suitable wrist pin 83 with the projecting flange 84 of a ring 85 mounted upon the periphery of the clutch member 66 for free rotation relative thereto. A pawl 86 pivotally mounted upon the wrist pin 83 engages the ratchet 87 formed integral with the driving clutch member 67. By the oscillating engagement of the paw] 86 with the ratchet 87 rotary motion is imparted to the clutch member 67 to drive the shaft 44. Pivot-ally attached 'to the eccentric strap 81 by wrist pin 88 is' aconnecting rod 89 the other end of which is attached by a wrist pin 90 with the projecting 'flange 91 of a second ring 92 mounted upon the clutch member 66. Mounted upon the flange 91 is a second pawl 93 arranged to eugage the ratchet 87 in such manner that the two pawls 86 and 93 actv alternately to produce substantially continuous'rotation of the shaft ratchet 87. This shield 95 is vrotatably `adjustable about the axis of theratchet and controls the engagement of the pawls 86 and 93 therewith thereby regulating the rate of rotation of the shaft 44. An armq96 projecting from the shield 95 carries a spring` pressed detent 97adapted to engage either of a plurality of apertures in a segmental flange 98 of the machine frame to hold the shield 95 in the preferred position of adjustment about its axis. Such ratchet vcontrolling mechanism is fully illustrated and described in `my VPatent No. 1,247,419, and a more complete disclosure at this time is not thought to be required. In the customary method of operation the cutter bar 24 is first thrust longitudinally into the coal body tomake the sumping, or entering cut, after which the machine is movedlaterally across the coal face to form a kerf therein. j To make the sumping cut the machine is positioned upon the mine floor with the cutter arm 24 projecting into the corner of the mine room, as illustrated in Fig. 9. The levers 42 are then moved to"4 disengage' the pinions 46 and 47 from the internal gears of the drums v36 land 37. The ropes 38 and 39 may then be drawn out from theirrespective drums vand their free ends attached to the anchor jacks 99 and 100 which are suitably placed adjacent ythe Vcoal face 101. Guide rollers 102and 103 are mounted at the forward corners of the machine frame to engage the 'feed ropes and prevent their chafing against the corners of the frame casting. After the ropes 38 and 39 are suitably'anchored the levers 42 are again moved to restore engagement of the pinions 46 and 47 with the drums 36 and 37. VVhe-n now the cutter chain is actuated manipulation of the hand wheels 65vand 79 will cause engagement of the friction clutches to simultaneously actuate both winding drums -to wind their respective ropes and thereby 4draw the machine bodily longitudinally forward to force the cutter bar 24 into the coal. The direction of movement of thecutter arm may be controlled by manipulation of one or other of the hand wheels 65 or 79 to permit more or less slippage in one or other of the friction clutches.

After the cutter. arm 24 has been fully sumped, the rope 39 may be disconnected anchor j ack 104 positioned at the left hand rib adjacent the coal face 101, as shown in Fig. 10. AThe rope 38 may be disconnected from the anchor jack 99 and attached to an anchor jack 105 positioned adjacent the right hand rib at a suitable distance from the face 101. Vhen so arranged the hand wheel 7 9 may be manipulated to actuate the drum 37 to draw the machine toward the left hand rib, and the hand wheel65 manipulated to permit the unwinding of the rope 38 from the drum 36 under frictional resistance to maintain the balance of forces and thereby hold the machine in the desired angular relation to the coal face.

A preferred arrangement for operating the machine from left to right is shown -in F igure 11. According to this figure, the cutter bits are reversed in theirsockets and the motor is reversed to give the chain the proper direction of movement. Reversal of the motor will cause reversal in the direction of rotation of ydrum 36, but in view of the pawl and ratchet connections bet-Ween this drum and the feed drum 37, the latter will be rotated in the same direction as when the motor is rotating in normal direction. Ihat is to say, drum 37 is capable only of unidirectional rotation, regardless of the direction of rotation of the moto-r.

It will be noted from Figure 1, as Well as from Figure 11, that a bollard 110 is positioned immediately in front of drum 36, this bollard being of the same form as that shown at 112, Figure 2. As shown in'Figure 11, feed rope 89 is passed around bollard 110 between the latter and drum 36, carried forward around sheave 102 and secured to a suitable anchor jack 113 at the right hand rib. Rope 38 is entirely unwound from drum 36 and rewound thereon in the opposite direction. Its free end is passed in contact with sheave 111, Figures 1, 2 and 11, and secured to a suitably disposed anchor j ack 114:. The manipulation of the machine with the elements in the described arrangement, will be controlled in exactly the same manner as has been described in connection with Figi ure 10.

It is to be understood that I do not limit myself to the precise construction or to the manipulations here illustrated and described, as the mechanism may be subject to wide variation as to detail without departure from the spirit of my invention.

IVliat- I claim is: Y

1. In a machine of the class described, the combination with a frame, of a motor mount ed thereon, a shaft rotatably mounted upon said frame, devices adapted to transmit roe tative power from said motor to said shaft including a friction clutch, a thrust collar screw threaded to an element of said frame adapted to cause engagement of the friction .elements of said clutch,y a sprocket wheel on said collar, an endless chain engaging said sprocket wheel, and means to actuate said chain to rotate said collar and thereby control the actuation of said clutch as and for the purpose set forth.

2. In a machine ofthe class described, the combination with a frame, of a mot-or mounted thereon, a shaft rotatably mounted upon said frame, devices adapted to transmit rotat-ive power from said motor to said shaft including a friction clutch mounted coaXi-ally with said shaft, a thrust collar screw threaded toan element of said frame adapted to cause engagement of the friction elements of said clutch, a sprocket wheel on said collar, an endless chain engaging said sprocket wheel, and means to actuate said chain to rotate said collar and thereby control the actuation of said clutch as and for the purpose set forth.

3. In a machine of the class described, the combination with a frame, of a motor mounted thereon, ashaft rotatively mounted on said frame, devices adapted to transmit rotative power from said motor to said shaft including a friction clutch, a thrust collar screw threaded to an element of said frame adapted to cause engagement of the friction elements of said clutch, a sprocket wheel on said collar, an endless chain engaging said sprocket wheel, and manually actuated means to actuate said chain to rotate said collar and thereby control the actuation of said clutch as and for the purpose set fort-h.

4. In a machine of the class described, the combination with a frame, of a motor mounted thereon, a shaft rotatably mounted on said frame, devices adapted to transmit rotative power from said motor to said shaft including a friction clutch mounted coaxially with said sb aft, a threaded sleeve on the frame coaxial with said shaft, a screw threaded thrust collar engaged on said threaded sleeve and displaceable therealong upon rotation in opposite directions to cause the engagement of the friction elements of said clutch, a sprocket Wheel on said thrust collar, an endless chain engaging said sprocket wheel, and means to actuat-e said chain to rotate said collar and thereby control the actuation of said friction clutch as and for the purpose set forth.

5. In a machine of the class described, the combination with a frame adapted to rest upon and slide in any direction over the floor of a mine, of a kerf cutter projecting horizontally therefrom, feeding and guiding mechanism comprising two flexible draft elements adapted to cooperate with anchoring devices external of the machine, two winding drums rotatably mounted upon the frame on parallel aires adapted to wind said draft elements, continuously acting power transmission devices including a drum engaging shaft and a coaxial rotary member adapted to transmit rotative power from said motor llO to one of said drums, a separate drive shaft engaged with the other drum and power transmitting devices including intermittently acting means adapted to transmit rotative power from said rotary member to said last named drum driving shaft as and for the purpose ser forth.

6. In a machine of the class described, the combination with a frame adapted to rest upon and slide in any direction over the floor of a mine. of a. kei-f cutter projecting horizontally therefrom, feeding and guiding mechanism comprising two flexible draft elements Vadapted to cooperate with anchoring devices external of the machine, two winding drums rotatably mounted upon the frame on parallel aries adapted to wind said draft elements, continuously acting power transmitting devices including a drum engaging shaft and` a coaxial' rotary member adapted to transmit rotative power from said motor to oneof said drums, friction devices interposed between said rotary member and said shaft adapted to control the winding and unwinding of said draft element by said one Vof the drums', and aA separate driving shaft engaged with the other drum and power transmittingcdevices including intermittently acting means adapted to transmit rotative power from said rotary member to said last named drum driving shaft as and for the purpose set forth.

7. In a machine of the class described, the combination with a frame adapted to rest upon and slide in any direction over the floor of a mine, of a korf cutter projecting horizontally therefrom, feeding and guiding mechanism comprising two flexible draft elements adapted'to cooperate with anchoring devices external of the` machine, two winding drums rotatably mounted upon said frame adapted to Vind said draft` elements, continuously acting power transmission `devices adapted to transmit rotative power from said motor to one of said drums, intermittently acting constant direction power transmission devices adapted to transmit ro-Y tative power to the other drum, andfriction devices interposed between said transmission de es and said drums to control the winding and unwinding of said draft elements as and for the purpose set forth.

S. AIn machine of the class described, the combination with a frame adapted to rest upon and slide in any direction over the floor Y of a mine, of a lerf cutter projecting hoiizontally therefrom, feeding and vguiding mechanism ci'vmprising two flexibleV draft ele.- iuents ad ated to vcooperate with anchoring de fi'ces ernal of the machine, two winding drums rotatably mounted upon the frame adapted to wind said draft elements, continuously acting power transmission devices adapted to transmit rotative power from said motor toyone of said drums, intermittently acting constant direction power transmitting devices adapted to transmit rotative power to the other drum, and means to permit the'unwinding of said draft elements as and for the purpose set forth.

9. In a machine of the class described,'the` combination `with aframe adaptedto rest upon and slidein any direction over the floor of a mine, ofV a kerf cutter projecting hori- Zontally therefrom, feeding 'and guiding mechanism comprising'two flexible draft elements adapted to cooperate ,with anchoring devices external of the machine, two winding drums rotatably mounted upon'the frame adapted to wind said draft element, continuously actingpowertransmission devicesl 'transmission devices and' saidv drums to control the winding and unwinding of said draft elements, and means to permit the free unwinding ofvsaid draft elements as and for the purpose set forth. l L

10. VIn a machine ofthe class described, the combination with aframe adapted to rest upon and slide-in any direction over the floor of a mine, a kerf cutter projecting horizontallytherefro-m, a motor mounted upon said frame and connected with said kerf cutter, feeding and guiding mechanism comprising two flexible draft elements adapted to cooperate with anchoring devices external of the machine, two winding drums rotatably mounted on said frame and adapted to wind said draft elements, gearing arranged to transmit rotative power from said motor to one of said drums, a friction clutch interposedbetween said gearing and saiddrum, means to actuate said frictionV clutch to control the winding andrunwinding of the draft element, and ratchet mechanism adapted to transmit rotative power to the other drum as and for the purposeset forth.

` ll; In a machineof the class described, the combinationwith a frame adapted to rest upon and slide in any direction over the floor of a mine, a kerf cutter projecting horizontally therefrom, a motor mounted onsaid frame and connectedV with said kerf cutter, feeding and guiding mechanismv comprising two 'flexible draft elements adapted' to cooperate with anchoring devices external -ofl the machine, ltwo winding drums rotatably mounted on said frame adapted to wind said draft elements, gearing arrangedto transmit j rotative power from said motor to one of said drums, ratchet mechanism adapted totrans- -mit rotative power to the other drumfriction clutches interposedbetween said transmission devices and said drums, and manuallyactuated means to control said friction clutches to control the windingand unwinding of said fleirible draft elements as and forfth'e purpose set forth.

12. In a miningmachine, the'coinbination with afsiipporting frame adapted to rest upon and slidey in any direction over the ioor of a mine, a motor mounted thereon, mining mechanism 'carried by said frame and actuated by said motor, feeding and guiding mechanism including two flexible draft elements adapted to cooperate with anchoring devices external of the machine,two winding drums rotatably mounted upon said frame on which said draft elements are wind'able, gearing arranged to transmit rotative power from vsaid motor to one of said drums, and ratchet mechanism adapted to transmit rotative power to the other drum as and for the purpose set forth.

13. In a mining machine, the combination with a frame adapted to rest upon and slide in any direction over the ii'oor of a mine, a motor :mounted thereon, mining mechanism carried by said frame and actuated by said motor, feeding and guiding mechanism including two iiexible draft elements adapted to cooperate with anchoring devices external of the machine,two winding drums rotatably mounted upon said frame on which said draft elements are windable, worm gearing arranged to transmit rotative power from said motor to one of said drums, and ratchet mechanism adapted to transmit rotative power to the 'other Jdrum as and for the purpose set fort-h.v Y c 14. Invia 'mining machine, the combination with a. frame adapted to rest upon and slide in any direction over the floor of a mine, a motor mounted thereon, mining mechanism carried by said frame and actuated by said motor, feeding and guiding mechanism including two flexibledraft velements 'adapted to cooperate with anchoring devices external of the machine, two winding drums rotatably mounted on said frame on which said draft elements :are windable, worm gearing arranged to transmit rotative power from said motor to one of said drums, v`and ratchet mechanism adapted to transmit rotativepower to the other drum as and for the purpose set forth. y Y

1151. kIn a mining machine, the combination with a frame adapted to rest upon and slide in 'any direction over the floor of a mine, a motor mounted thereon, mining mechanism carried by said frame and actuated by said motor, feeding and guiding mechanism including two tieXible draft elements adapted to cooperate with anchoring devicesexternal of the machine, two winding drums rotatably mounted upon said frame on which said draft elements are windable, worm ygearing 4arranged yto transmit rotative power from said motor to'one of said drums, andratchet mechanism actuated by said 1vorm gearing adapted totransmit rotative power :to the otherolrum as and for the purpose'setforth.

res-isti said frame, feeding and guiding mechanismy comprising two shafts rotatably mounted on said frame, gearing including a friction clutch adaptedto transmit rotative power from said motor toone of said shafts, ratchet mechanism actuated by said gearing, a fric-- tion clutch arranged to connect said ratchet mechanism with the other shaft to rotate it, a winding drum connectible with each of said shafts, andfleXible draft elements windabie upon said drums adapted to cooperate with anchoring devices external of the machine as and for the purpose set forth.

17. In a machine of the class described, the combination with frame adapted to rest upon and slide in any direction over the floor of a mine, a kerf cutter projecting horizontally therefrom, feeding and guiding mechanism comprising two flexible draft elements adapted to cooperate'withanchoring devices external of the machine, two winding drums rotatably mounted on vertical axes upon said frame and 'adapted to wind said draftelements, means to 'cause the rotation Aof one of said drums in either direction, and means to cause simultaneous rotation of the other drum in a winding direction as and for the purpose set forth.

18. In a machine of the class described, the

combination with a frame adapted to rest upon and slide in any direction over the floor of a mine, a lre'rf cutter projecting horizon- 'tally therefrom, a motor mounted upon said frame, feeding and'. guiding mechanism comprising two iiexible draft elements adapted to cooperate with anchoring devices external of the machine, two winding drums rotatably mounted on vertical axes upon said frame and adapted to wind said draft elements, means to connect one of said drums with said motor to cause its rotation in a direction depending upon the direction of rotation of the armature of the motor, and means to connect the other drum with the motor to cause its simultaneous rotation in a winding direction regardless of the direction of motor rotation as and for the purpose set forth.

19. In 'a machine of the class described, the

cembinati'on with a frame adapted to rest upon 'and' slide in `any direction over the licor of a mine, of a lrerf cutter projecting horizontally therefrom, feeding and guiding mechanism comprising two flexible draft eledevices external of the machine, two winding drums rotatably mounted upon spaced apart vertical axes symmetrically disposed 'upon said frame and adapted to wind said ico Vments adapted to cooperate with anchoring draft elements, means to cause rotation of one of said drums in a winding direction and means to siniultaneouslyk cause rotation of the other drum in an unwinding direction as and for the-purpose set forth.

20. In a machine of the class described, the combination with a frame adapted to rest uponand slide in any direction over the floor of a mine, of lerf cutter projectinghorizontally therefrom, feeding and guiding mechanism comprising two iieXible draft elements adapted to cooperate with anchoring devices externali of the machina-two winding drums rotatably mounted on spaced .part vertical axes symmetrically disposed a plane extending transversely of the machine and adapted to wind said draft elements, means to cause rotation of one of said drums in a winding direction and means to simultaneously cause Vrotation of the other drum in an unwinding direction as and for the purpose set forth.

Q1. In a machine of the class described, the combination with a frame adapted to rest upon d slide in any direction over the iioor of mine, a lrerf cutter projecting horizontherefrom, motor mounted upon said ne co nected with said lfrerf cutter, feedin51 mechanism comprising two flexible draft elements adapted to cooperate with anchoring devices external of the mae, two winding drums rotatably mounted upon said frame adapted to wind said draft enients, power transmitting devices includfriction clutches adapted to transmit ro- L\ e power from said motor to said drums, thrust collars screw threaded to elements of said fr(n ne adapted to cause engagement of the Y n elements of said clutches, and convenient to the hand of the operator n ed to rotate said thrust vcollars and control the actuation of said friction f for the purpose set forth. 22. In a machine of the class described, the combination with a frame adapted to rest upon and slide in any direction over the floor of a mine, a kerf cutter projecting horizontally therefrom, a motor mounted upon said frame connected with said lrerf cutter, feeding and guiding mechanism comprising two flexible draft elements adapted to cooperate with anchoring devices externa-l of the machine, two winding drums rotatably mounted upon said frame adapted to wind said draft elements, power transmitting devices including two friction clutches adapted to transmit rotative power from said motor to said drums, thrust collars screw threaded to elements of said frame adapted to cause engagement of the friction elements of said clutches and control devices positioned convenient to the hand of the operator external of said frame adapted to rotate said thrust collars and thereby control the actuation of said friction clutches, as and for the purpose set forth.

28. In Va mining machine, the combination with a frame adapted to be moved over a mine floor; a vmotor mounted on said frame, a pair of drums mounted on said frame, a rotatable drive element for one of said drums, power connections betweensaid motor and said drive element, and driving connections between said drive element and the other of said drumsV including a pawl and ratchet device. f i

24:. InY a mining machine` the combination with a frame adapted to be moved over a mine floor, Va motor mounted onsaid frame, a pair of drums mounted. on said frame, a rotatable drive elementfor one of said drums, power connections between said motor and said drive element for rotating the latter in either direction. and constant direction drivand the other of said drums.V

25. In a, mining machineithe combination mine floor, a motor mounted on said frame, a pair of drums mounted on said frame` a rotatable drive element for one of said drums and mounted in concentric relation thereto, power connections between said motor and said drive element for rotating thelatter in either direction, constant direction driving connections between said drive element and the other of said drums, and clutch means between said drive element and its associated drum. Y

26. In a mining machine. the combination with a frame adaptedto be'moved over a mine iioor, a motor mountedvon-said frame, a pair of drums mounted on said frame, a

rotatable drive element for one of said drums,

power connections between said motor and said drive element for rotating the latter in either direction, and pawl and ratchet transmission means between said drive element and the other drum, whereby a unidirectional drive is imparted to the latter. y

27. In a machine of the class described, lthe combination with aV frame adapted tobe moved over a mine floor, of a shaft journaled in bearings on the frame, one of said shaft bearings having an external cylindrical portion provided with screwl threads, an internally threaded thrust collar engaged on said cylindrical portion for reciprocation there along upon relative rotation in opposite directions, a drumadapted to be driven by said shaft,a rotary driven element coaxial with said shaft and freely rotatable relative thereto, a clutch interposed between said driven elements and said shaft and controlled by said thrust collar in its reciproca-tory movements, and means to rotate said thrust collar.

28. In a machine of the class described, the

combination with a frame adapted to be* moved over a mine fioor, of a shaft journaled in bearings on the frame, one of said shaft bearings having an external cylindrical portion provided with screw threads, an internally threaded thrust collar engaged on said ing connections between said driveA elementV cylindrical portion for reciprocation there along upon relative rotation in opposite directions, a drum adapted to be driven by said shaft, a rotary driven clement coaxial with said shaft and freely rotatable relative thereto, a friction clutch interposed between said driven elements and said shaft and controlled by said thrust collar in its reciprocatory movements, and means torotate said thrust collar.

29. In a machine of the class described, the combination with a frame adapted to be moved over a mine floor, of a pair of vertical shafts journaled in bearings on the frame in side by side relation, a rotary driven element coaxial with one of said shafts and freely rotatable relative thereto, an eccentric Vform-- ing a part of said driven element, a clutch operable to connect said driven elements with its associated shaft, a ratchet wheel freely rotatable on the other of said shafts, a palwl actuated by said eccentric cooperable with said ratchet wheel, a clutch operable to connect said ratchet wheel with its associated shaft, and drums adapted to be driven by said shafts.

30. In a machine of the class described, the combination with av frame adapted to be moved over a mine floor, of a pair of vertical shafts journaled in bearings on the frame in side by side relation, a rotary element coaxial with one of said shafts and freely rotatable relative thereto, said rotary element including a'worm gear and an eccentric, a worm engaged with said gear to drive the rotary element, a. clutch operable to connect said rotary element with its associated shaft, a ratchet wheel freely rotatable on the other of said shafts, a pa-wl actuated by said eccentric and coop'erable with said ratchet wheel, a clutch operable to connect said ratchet wheel with its associated shaft, and drums adapted to be driven by said shafts.

3l. In a mining machine, a rear end construction comprising a relatively thin shoe adapted to rest slidably on a mine floor, a frame element spaced above the shoe, and a pair of drums mounted directly above said shoe on vertical axes and at opposite sides of the longitudinal axis of the machine, the drums being bounded upwardly and downwardly by the same horizontal planes, the lower of said planes being spaced from the shoe portions immediately below the drums only sufficiently to provide free running clearance for the drums.

32. In a mining machine, a rear end construction comprising a relatively thin shoe adapted to rest slidably on a mineL floor, a frame element spaced above the shoe, a pair of vertical pins connecting the frame element and shoe to prevent relative displacement of the two away fromA each other, said pins being mounted on opposite sides of the longitudinal axis of the machine, and a drum rotatable about each of said 'pins directly above the shoe.

In a mining machine, a rear end construction comprising a relatively thin shoe adapted to. rest slidably on a mine Hoor, a frame element spaced above the shoe, a pair of vertiz; al pins connecting the frame element and shoe and constituting tension and compression members, said pins being mounted on opposite sides of the longitudinal axis of the machine, and a drum rotatable about each of said pins directly above the shoe.

34. In a mining machine, a rear end construction comprising a relatively thin shoe adapted to rest slidably on a mine floor, a frame element spaced above the shoe, a pair of vertical pins connecting the frame element and shoe and constituting tension and compression members, said pins being mounted on opposite sides of the longitudinal axis of the machine, a hub mounted eccentrically on each of said pins, an operating lever for each `hub projecting laterally of the machine, and a drum rotatable on each ofv said hubs directly above the shoe.

35. In a mining machine, a rear end construction comprising a relatively thin shoe adapted to rest slidably on a mine floor, a hol'- low frame element spaced above the shoe, a pair of vertical shafts journaled in said hollow frame element with their lower ends proecting therebelow, said shafts being disposed on opposite sides of the longitudinal axis of the machine, a drum positioned below each of lsaid shafts directly above the shoe, and driving means between the shaft ends and the respective drums.

36. In a mining machine, a. rear end construction comprising` a relatively thin shoe adapt-ed to rest slidably on a mine floor, a hollow frame element spaced above the shoe, a pair of vertical shafts journaled in said hollow frame element with their lower ends projecting therebelow, said shafts being disposed on opposite sides of the longitudinal anis of the machine, a drum positioned below each of said shafts directly above the shoe, internal teeth on the drums, and teeth on said projecting shaft ends adapted to engage the respective drum teeth.

37. In a mining machine, a rear end construction comprising a relatively thin shoe adapted to rest slidably on a mine jioor, a frame element spaced above said shoe, a pair of drums mounted directly above said shoe on vertical axes and at opposite sides of the longitudinal aXis of the machine, a pair of .vertical shafts journaled inthe frame element, means including frictional clutches on the shafts above the drums for imparting rotation to said shafts, and driving connections between the shafts and respective drums.

38. A mining machine comprising a. supporting frame having spaced apart base and top sections, means comprising a fixed bearing for rigidly connecting said sections against relative displacement, a rope drum, a journal bearing for said rope drum and eccentrically mounted on said fixedV bearing, means V'for driving said rope drum, and mechanism for shift-ing said journal bearing about said fixed bearing to render inoperative said driving means and freeing said `rope drum.

39. A mining machine comprising frame sections spaced-apart, a fixed bearing having shoulders at its ends fitting in recesses in said frame sections to resist compression strains, means for securing the ends of said bearing to said sections to resist tensional strains, a rope drum, a journal bearing for said rope drum and eccentrically mounted on said fixed bearing, driving mechanism for said rope drum, and means for shifting said journal bearing to render inoperative said driving mechanism and thereby free said rope drum.

40. A mining machine comprising a feeding and guiding unitk having upper and lower frame sections, spaced-apart vertical bearings rigidly connecting said frame sections, a feeding rope drum and a guiding rope drinn, journal bearings for said drums' respectively eccentrically mounted on said fixed bearings, independent means for driving said rope drums, and means for independently freeing said rope drums by independently rendering inoperative said rope drum driving means. L

4l. In a shortwall mining machine, the combination with a supporting frame, of kerf cutting mechanism mounted thereon, a feeding rope drum, a guiding rope drum, means for rotating said guiding rope drum in either direction, and power transmission mechanism connected to the feeding rope drum to always rotate the same in feedingy direction irrespective of the direction of rotation of said guiding rope drum.

42. In a shortwall miningv machine, the combination with a supporting frame, 'of kerf cutting mechanism mounted thereon, guiding mechanism comprising a rope drum, a motor, power transmission mechanism between said motor and said rope drum, feeding mechanism comprising another rope drum, and connections between said power transmission mechanism and said last-named rope drum to secure rotation of the latter always in the same direction whether the firstnamed rope drum is rotated in one direction or the other.

43. In a shortwall mining machine, the combination with a frame adapted to rest on and slide over a mineoor, of kerf-cutting mechanism projecting from the forward end of said frame, guiding mechanism comprising a rope drum, a reversible motor connected to said rope drum to drive the same in either direction, feeding mechanism comprising another rope drum, and means comprising an eccentric rotatable with said firstnamed rope drum and connected* to Saidfeeding mechanism to secure rotation of said second-nanied rope drum always in the same diu rection irrespective of the direction of rotation of said first-named rope drum. f

44. In lashortwalliniiiing machine, the

combination with a frame adapted to rest'on and .slide over a mine floor, of kerf-cu'ttingV Vmechanism mounted thereon, guidingmechanisin comprising a'rope drum, means for driving said rope drum ineither" direction, feeding mechanism comprising another rope drum ,andratchet' feeding means therefor,A

Vand eccentricdriving means connected'between saidV first-named rope .drumpand said ratchet feedingmeans to -secure'rot'ation of fthe feeding ropedrum alwaysin the same direction irrespective of thedirection o f'rof tation of the guiding rope drum.

45. In a mining machine, the combination with ai supporting frame adapted .to rest on and slide over the mine licor, of'ker'f cutting mechanismen the forward endof said frame, r

feeding and guiding mechanismen the rear `end of said frame comprising an pair ofrope drums mountedfor rotation on vertical axes, a motor oii said frame, a single longitudinal shaft connecting said motor to said cutting mechanism and extending to a position lloetween the aires ofsaid rope drums, driveconnections for one of said drums including inktermes'hing gea'ringof which a drive element feeding. and guiding mechanism on the'rear end of saidv frame comprising a pair lof rope drums mounted for rotation onv vertical axes,y a motoren said frame, a single longitudinal shaft connecting VsaidV motor to Y said cutting mechanism and eXtendingto-aposition be- -is on said shaft, and drive connections for tween the axes ef said rope drums, driveconnections for one of saiddrums'including intermeshing gearing of which a drive element is on said shaft, and drive connections for the other of. said drums including pawl and ratchet mechanisml driven from a driven member of said intermeshing gearing.

lZJIn a Vmining machine, the combination with a supporting frame adapted to reston mechanism on the forward end of said frame, feeding and guiding mechanism on the rear drums mounted for rotation'on vertical axes, a motor on said frame, asingle longitudinal shaft connecting said motor to said cutting :mechanism and.y extending to fa. position be.- .tween the .axes o f-said rope drums, drive 'cont .and slide over the mine floor, of kerfcutting end of saidframe comprising a pair of :rope

nections for one of said drums including lntermeshing gearing of which a drive element 1s on said shaft, and drive connections for the other of said drums including pawl and ratchet mechanism driven from a driven member of said intermeshing gearing, each of said drive connections also including an independently operable friction clutch.

48. In a mining machine, the combination with a supporting frame adapted to rest on vand slide over the mine fioor, of kerf cutting mechanism on the forward end of said frame,

feeding and guiding mechanism on the rear end of said frame comprising a pair of rope drums mounted for rotation on vertical axes, al motor on said frame, a single longitudinal shaft connecting said motor to said cutting mechanism and extendingtoa position between the axes of said rope drums, a worm on said shaft, a worm wheel driven by said worm and adapted to drive one of said drums, and mechanism driven by said worm wheel 4and adapted to drive the other of said drums.

49. In a mining machine, the combination witha supporting frame adapted to rest on and slide over the mine floor, of kerf cutting mechanism on the forward end of said frame,

feeding and guiding mechanism on the rear end of said frame comprising a pair of rope drums mounted for rotation on vertical axes, a motor on said frame, a single longitudinal shaft connecting said. motor to said cutting `mechanism andextending to a position between the axes of said rope drums, a worm on said shaft, a worm wheel driven by said worm and adapted to drive one of said drums, and pawl and ratchet mechanism driven by said' Worm wheel and adapted to drive the other of said drums.

50.` In a mining machine, the combination with a supporting frame adapted to rest on my hand.

y NILS D. LEVIN.

and slide over the mine door, of kerf cutting mechanism on the forward end of said frame,

feeding and guiding mechanism on the rear end of said frame comprising a pair of rope drums mounted for rotation on vertical axes, Va motor on said frame, a single longitudinal shaft connecting said motor to said cutting mechanism and extending to a position betweenA the axes of said rope drumsa worm on saidlshaft, a worm wheel driven by said worm and adapted to drive one of said drums, and mechanism driven bysaid worm wheel and adapted. to drive the otherl of said drums, the drive for each drum including an independently operable friction clutch.

51. Ina mining machine, the combination with a supporting frame adapted to rest on and slide over the mine Hoor, of kerf cutting mechanism on the forward end of said frame, feeding and guiding mechanism on the rear end of "said frame comprising a pair of rope drums mounted for rotation on vertical axes, amotor `on saidframe, a single longitudinal shaft connecting said motor toV said cutting rums, 

